阅读说明：本技术 一种苯甲醚制取茴香基丙醛的方法 (Method for preparing anisyl propionaldehyde from anisole ) 是由 李良龙 李威宏 于 2020-04-16 设计创作，主要内容包括：本发明涉及有机合成技术领域,特别是涉及一种苯甲醚制取茴香基丙醛的方法,包括：将苯甲醚和2-甲基烯丙基二乙酸酯或苯甲醚、2-甲基丙烯醛和醋酐加入反应容器中催化反应,再用碱性水溶液混合洗涤,将油相进行减压蒸馏,将1-乙酰氧基-2-甲基-3-(4-甲氧基苯基)丙烯加入带有醇溶剂和酯交换催化剂的反应容器中进行酯交换反应,常压蒸馏得到茴香基丙醛。本发明解决现有技术中原料大茴香醛或者茴香醇价格昂贵导致产品茴香基丙醛价格居高不下的问题,由苯甲醚合成茴香基丙醛,苯甲醚便宜易得,生产流程短,三废产生量少,经济而又环保。合成的茴香基丙醛具有足够高的纯度,可用于香料。(The invention relates to the technical field of organic synthesis, in particular to a method for preparing anisyl propionaldehyde from anisole, which comprises the following steps: adding anisole and 2-methyl allyl diacetate or anisole, 2-methylacrolein and acetic anhydride into a reaction vessel for catalytic reaction, mixing and washing with alkaline aqueous solution, carrying out reduced pressure distillation on an oil phase, adding 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene into the reaction vessel with an alcohol solvent and an ester exchange catalyst for ester exchange reaction, and carrying out normal pressure distillation to obtain anisyl propionaldehyde. The invention solves the problem that the price of anisyl propionaldehyde is high due to the high price of the raw material anisyl aldehyde or anisyl alcohol in the prior art, and the anisyl propionaldehyde is synthesized from anisole, wherein the anisole is cheap and easy to obtain, the production flow is short, the generation amount of three wastes is small, and the method is economical and environment-friendly. The anisylpropionaldehyde synthesized is of sufficiently high purity to be useful in perfumery.)

1. A method for preparing anisyl propionaldehyde from anisole is characterized by comprising the following steps:

step one, anisole and 2-methyl allyl diacetate are mixed according to the molar ratio of (5-8): 1, adding the mixture into a reaction container, cooling to-10-40 ℃, adding an alkylation reaction catalyst, and reacting at-10-80 ℃ until the residual amount of 2-methylallyl diacetate is less than 1%, thus obtaining a mixture for later use;

step two, mixing and washing the mixture obtained in the step one with an alkaline aqueous solution, transferring the oil phase into a solvent recoverer, and carrying out reduced pressure distillation to obtain 1-acetoxyl group-2-methyl-3- (4-methoxyphenyl) propylene for later use;

adding 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene into a reaction container with an alcohol solvent and an ester exchange catalyst, reacting at 10-80 ℃ until the residual amount of 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is less than 1%, and distilling at normal pressure to obtain anisyl propionaldehyde.

2. The method for preparing anisyl propionaldehyde from anisole, as claimed in claim 1, wherein the 2-methylallyl diacetate is prepared by: 2-methylacrolein and acetic anhydride are mixed according to a molar ratio of 1: (1.0-1.4) adding the mixture into a reaction vessel, cooling to-10-40 ℃, adding an alkylation reaction catalyst, and reacting at-10-80 ℃ to obtain the 2-methylallyl diacetate.

3. The method for preparing anisyl propionaldehyde from anisole, as claimed in claim 1, wherein: in the first step, the molar ratio of anisole to 2-methylallyl diacetate is 6: 1; the adding temperature of the alkylation reaction catalyst in the first step is 5-30 ℃; the reaction temperature in the first step is 10-60 ℃.

4. The method for preparing anisyl propionaldehyde from anisole according to claims 1 to 3, wherein the alkylation reaction catalyst is at least one of Lewis acid and Bronsted acid.

5. The method for preparing anisyl propionaldehyde from anisole, as claimed in claim 1, wherein: the second step is specifically as follows: mixing and washing the mixture obtained in the step one with a sodium hydroxide aqueous solution with the mass fraction of 1%, removing a water phase, transferring an oil phase into a solvent recoverer, and performing reduced pressure distillation to recover anisole;

the third step is specifically as follows: adding an alcohol solvent and an ester exchange catalyst into a reaction container, dropwise adding 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene into the reaction container at the dropwise adding temperature of less than or equal to 40 ℃, reacting at 10-80 ℃ after dropwise adding until the residual amount of 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is less than 1%, distilling at normal pressure to recover the alcohol solvent to obtain a crude anisyl propionaldehyde product, and then carrying out reduced pressure fast distillation and rectification on the crude anisyl propionaldehyde product to obtain the finished anisyl propionaldehyde product.

6. The method for preparing anisyl propionaldehyde from anisole according to claim 1 or 6, wherein: the alcohol solvent in the third step is at least one of methanol, ethanol, n-butanol and n-propanol; the ester exchange catalyst in the third step is at least one of potassium carbonate, sodium methoxide, dilute sulfuric acid, sodium carbonate, sodium acetate and hydrochloric acid.

7. A method for preparing anisyl propionaldehyde from anisole is characterized by comprising the following steps:

s1, mixing anisole, 2-methylacrolein and acetic anhydride according to a molar ratio of (5-8): 1: (1.0-1.4) adding the mixture into a reaction container, cooling to-10-40 ℃, adding an alkylation reaction catalyst, and reacting at-10-80 ℃ until the residual amount of 2-methylallyl diacetate is less than 1%, so as to obtain a mixture for later use;

s2, mixing and washing the mixture obtained in the step S1 with an alkaline aqueous solution, transferring an oil phase into a solvent recoverer, and carrying out reduced pressure distillation to obtain 1-acetoxyl group-2-methyl-3- (4-methoxyphenyl) propylene for later use;

s3, adding 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene into a reaction container with an alcohol solvent and an ester exchange catalyst, reacting at 10-80 ℃ until the residual amount of 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is less than 1%, and distilling at normal pressure to obtain anisyl propionaldehyde.

8. The method for preparing anisyl propionaldehyde from anisole, as claimed in claim 7, wherein: in the step S1, anisole, 2-methylacrolein and acetic anhydride are mixed according to a molar ratio of 6: 1: 1.2; the adding temperature of the alkylation reaction catalyst in the step S1 is 5-30 ℃; the reaction temperature in the step S1 is 10-60 ℃.

9. The method for preparing anisyl propionaldehyde from anisole according to claim 7 or 8, wherein the alkylation catalyst is at least one of Lewis acid and Bronsted acid; the alcohol solvent is at least one of methanol, ethanol, n-butanol and n-propanol; the ester exchange catalyst is at least one of potassium carbonate, sodium methoxide, dilute sulfuric acid, sodium carbonate, sodium acetate and hydrochloric acid.

10. The method for preparing anisyl propionaldehyde from anisole, as claimed in claim 7, wherein: the step of S2 is specifically: mixing and washing the mixture obtained in the step S1 with a sodium hydroxide aqueous solution with the mass fraction of 1%, removing a water phase, transferring an oil phase into a solvent recoverer, and performing reduced pressure distillation to recover anisole;

the step of S3 is specifically: adding an alcohol solvent and an ester exchange catalyst into a reaction container, dropwise adding 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene into the reaction container at the dropwise adding temperature of less than or equal to 40 ℃, reacting at 10-80 ℃ after dropwise adding until the residual amount of 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is less than 1%, distilling at normal pressure to recover the alcohol solvent to obtain a crude anisyl propionaldehyde product, and then carrying out reduced pressure fast distillation and rectification on the crude anisyl propionaldehyde product to obtain the finished anisyl propionaldehyde product.

Technical Field

The invention relates to the technical field of organic synthesis, in particular to a method for preparing anisyl propionaldehyde from anisole.

Background

Anisyl propionaldehyde, chemical name: 2-methyl-3- (4-methoxyphenyl) propanal, english name: 2-methyl-3- (p-methoxyphenyl) -propanal. CAS number: 5462-06-6, molecular formula C₁₁H₁₄O₂The appearance was colorless to pale yellow liquid. Anisyl propionaldehyde applianceHas fruity, fennel and flowery flavors, is widely applied to daily chemical essence, and has wide market prospect.

Anisyl propionaldehyde is mainly produced by international perfumery (IFF) usa, miraculin (Givaudan) switzerland, BASF, germany. The product is produced by deriving from a semi-synthesis process of heliotropin, wherein the heliotropin in the semi-synthesis process of heliotropin is changed into anisic aldehyde, and then the anisic aldehyde is obtained by condensing with propionaldehyde, hydrogenating and rectifying. The earliest anisyl propionaldehyde was applied to daily chemical essences and then gradually expanded into food essences. And then. The product has a small application range all the time, is not well popularized, and has low global demand.

Conventionally, anisyl propionaldehyde is produced by using anisic aldehyde as a raw material, wherein the anisic aldehyde is mainly derived from anethole extracted from anise oil, the anethole is subjected to catalytic oxidation to obtain the anisic aldehyde, and then the anisic aldehyde is subjected to aldol condensation and hydrogenation to obtain the anisyl propionaldehyde. The source of the anise oil is the anise oil regardless of taking the anisic aldehyde as the raw material or taking the anisic alcohol as the raw material.

In 2012, Chinese patent (patent No. CN201210570979.7) obtained the product by condensing anisic aldehyde and propionaldehyde and then carrying out catalytic hydrogenation under the action of palladium-carbon catalyst. In 2015, Chinese patent (patent No. CN2016100966571) obtained halide by reacting anisol with hydrohalic acid, and then alkylated with propionaldehyde, solid base and phase transfer catalyst to obtain anisyl propionaldehyde.

The semisynthesis process using anisic aldehyde as a raw material comprises the following steps: firstly, adding a methanol solution of alkali with the mass concentration of 1-20% and anisaldehyde into a reaction kettle, heating to 20-80 ℃, then dropwise adding n-propionaldehyde into the reaction kettle, keeping the temperature for reaction for 3-8 hours after dropwise adding is finished, monitoring the reaction by GC (gas chromatography), cooling to 20-30 ℃ after the reaction is finished, neutralizing the pH to 6-8 with acetic acid, distilling and recovering methanol, washing with water, removing a water layer, and rectifying an oil layer to obtain unsaturated aldehyde; putting the unsaturated aldehyde prepared in the previous step into a reaction kettle, adding a catalyst and ethanol with the weight of 1-10%, heating to 80-130 ℃, introducing hydrogen, maintaining the pressure at 0.5-5.0 Mpa, reacting for 6-12 h, releasing the pressure after the reaction is finished, filtering the feed liquid, obtaining a crude product anisyl propionaldehyde by rectifying the crude product, and obtaining a finished product anisyl propionaldehyde.

A semi-synthesis process using anisic aldehyde as raw material includes such steps as Claisen-Schmidt condensation with propionaldehyde under alkaline condition, hydrogenation and rectifying. The semi-synthesis process using anisic aldehyde as a raw material has a very low yield and many process problems. If liquid alkali is used as a catalyst, a large amount of salt-containing wastewater can be caused due to the fact that the liquid alkali cannot be recycled, and post-treatment is complex; although the condensation process is improved, such as the use of a phase transfer catalyst, the phase transfer catalyst also has the problems of expensive catalyst, incapability of recycling, difficult material separation and the like. If solid alkali is used as a catalyst and the reaction is carried out in a methanol or ethanol solution, a large amount of solvent needs to be recovered, and the solid alkali waste is difficult to treat. The hydrogenation reaction adopts catalytic hydrogenation, and a process of adopting cheap Raney nickel for catalytic hydrogenation is not reported, and palladium-carbon catalysts are basically adopted for catalytic hydrogenation, so that the problem of high cost of the catalysts exists; if chemical reagents are used for hydrogenation, more problems are caused, such as expensive catalysts, large amount of three wastes, poor safety and the like. The hydrogenation reaction has the problems of poor selectivity, low yield of anisyl propionaldehyde and high content of anisyl propanol serving as a byproduct.

The semisynthesis process using anisyl alcohol as a raw material comprises the following steps: firstly, adding hydrohalic acid into anisyl alcohol, and stirring and reacting for 1-3 hours at the temperature of 5-20 ℃ to obtain p-methoxybenzyl halide; adding a toluene solvent, powdery sodium hydroxide and a phase transfer catalyst into a reactor, slowly adding p-methoxybenzyl halide and propionaldehyde into the reactor, and reacting at 60-110 ℃ for 12-16 h to obtain the anisyl propionaldehyde product.

The semi-synthesis process using the anisyl alcohol as the raw material uses a large amount of halogen acid, has high requirements on equipment, poor process safety, difficult post-treatment of solid alkali, generates a large amount of salt-containing wastewater, has expensive phase transfer catalyst, is difficult to realize recycling, is difficult to separate materials, has long process time, has more side reactions and low product yield. Meanwhile, anisyl alcohol is generally prepared by taking anisaldehyde as a raw material through catalytic hydrogenation or Cannizzaro reaction (Cannizzaro), the reported mass yield is generally about 80%, so that the cost of the raw material (anisyl alcohol) is high, and the anisyl propionaldehyde prepared by the route is expensive.

In the prior art, the synthesis process of anisyl propionaldehyde has a big problem: the price of the raw material anisic aldehyde or anisic alcohol is high, so that the price of the anisyl propionaldehyde product is high, and the market application cannot be expanded.

Disclosure of Invention

In view of the above disadvantages of the prior art, the present invention aims to provide a method for preparing anisyl propionaldehyde from anisole, which is used to solve the problem that the price of anisyl propionaldehyde is high due to the expensive price of anisyl aldehyde or anisyl alcohol in the prior art. The invention changes the traditional synthetic method taking anisic aldehyde or anisic alcohol as raw materials, the anisole as the raw material is cheap and easy to obtain, the production flow is short, the three wastes are less generated, the method is economic and environment-friendly, and the synthesized anisyl propionaldehyde has high enough purity and can be used for spice.

In order to attain the above and other related objects,

the first aspect of the invention provides a method for preparing anisyl propionaldehyde from anisole, which comprises the following steps:

step one, anisole and 2-methyl allyl diacetate are mixed according to the molar ratio of (5-8): 1, adding the mixture into a reaction container, cooling to-10-40 ℃, adding an alkylation reaction catalyst (Lewis acid and/or Bronsted acid), and reacting at-10-80 ℃ until the residual amount of 2-methylallyl diacetate is less than 1%, so as to obtain a mixture for later use;

step two, mixing and washing the mixture obtained in the step one with an alkaline aqueous solution, transferring the oil phase into a solvent recoverer, and carrying out reduced pressure distillation to obtain 1-acetoxyl group-2-methyl-3- (4-methoxyphenyl) propylene for later use;

adding 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene into a reaction container with an alcohol solvent and an ester exchange catalyst, reacting at 10-80 ℃ until the residual amount of 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is less than 1%, and distilling at normal pressure to obtain anisyl propionaldehyde.

The chemical name of anisyl propionaldehyde is 2-methyl-3- (4-methoxyphenyl) propionaldehyde, and the name of English is 2-methyl-3- (p-methoxyphenyl) -propanal. CAS number: 5462-06-6, molecular formula C₁₁H₁₄O₂The chemical structural formula is as follows:

the anisyl propionaldehyde has fruity, fennel and flowery odour, has obvious flowery sweet aroma compared with the essence with the fennel aroma such as anethole, anisaldehyde and the like, has the aroma of the fennel compared with the flowery odour essence, has soft and lasting aroma, and is a high-grade aroma raw material favored by a spice mixer. The perfume has application in some rare perfumes and cosmetics, especially food perfumes, and has special fragrance.

The anisole is used for synthesizing anisyl propionaldehyde, and as a brand new synthesis process, the traditional synthesis method using anisyl aldehyde or anisyl alcohol as a raw material is changed. The raw material anisole is cheap and easy to obtain, the production flow is short, the three wastes are less, and the method is economical and environment-friendly. The anisylpropionaldehyde synthesized is of sufficiently high purity to be useful in perfumery.

The reaction route of anisole and 2-methylallyl diacetate is depicted as the A synthesis route of anisyl propionaldehyde:

a synthetic route of anisyl propionaldehyde: adding anisole and 2-methylallyl diacetate into a reaction vessel, cooling to-10-40 ℃, adding an alkylation reaction catalyst (Lewis acid and/or Bronsted acid), and controlling the temperature to be less than 40 ℃ when adding the alkylation reaction catalyst. After the alkylation reaction catalyst is added, the reaction temperature is controlled between-10 ℃ and 80 ℃ for reaction until the residual quantity of the raw material 2-methyl allyl diacetate is less than 1 percent. After the reaction, an appropriate amount of aqueous sodium hydroxide solution was added for washing, and the aqueous phase was separated. Transferring the oil phase into a solvent recoverer, and performing reduced pressure distillation to recover the unreacted excessive anisole. And adding the intermediate 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene after the solvent is recovered into a reaction vessel, and then adding a proper amount of alcohol solvent and an ester exchange catalyst. Controlling the reaction temperature to be 10-80 ℃ for reaction until the residual quantity of the intermediate is less than 1%. After the reaction, the solvent was recovered by atmospheric distillation. And then adding water to wash the crude anisyl propionaldehyde, then carrying out vacuum fast distillation, and finally rectifying the fast distilled crude product to obtain the finished anisyl propionaldehyde.

In an embodiment of the present invention, the preparation process of the 2-methylallyl diacetate is as follows: 2-methylacrolein and acetic anhydride are mixed according to a molar ratio of 1: (1.0-1.4) adding the mixture into a reaction vessel, cooling to-10-40 ℃, adding an alkylation reaction catalyst, and reacting at-10-80 ℃ to obtain the 2-methylallyl diacetate. The reaction of 2-methacrolein and acetic anhydride produces 2-methallyl diacetate under conditions similar to those of anisole and 2-methallyl diacetate.

In an embodiment of the present invention, the molar ratio of anisole to 2-methylallyl diacetate in the first step is 6: 1; the adding temperature of the alkylation reaction catalyst in the first step is 5-30 ℃; the reaction temperature in the first step is 10-60 ℃.

In one embodiment of the present invention, the alkylation catalyst is a lewis acid and/or a bronsted acid. The alkylation reaction catalyst includes boron trifluoride, boron trichloride, boron tribromide, boron triiodide, boron trifluoride-acetic acid compound, boron trifluoride-diacetic acid compound, boron trifluoride-diethyl ether compound, boron trifluoride-tetrahydrofuran compound, boron trifluoride-acetonitrile compound, boron trifluoride-dihydrate compound, boron trifluoride-n-butyl ether compound, boron trifluoride-methyl alcohol compound, boron trifluoride-phenol compound, boron trifluoride-phosphoric acid compound and the like, metal chlorides such as aluminum trifluoride, aluminum chloride, lithium bromide, aluminum iodide, scandium chloride, scandium bromide, scandium iodide, gallium fluoride, gallium chloride, gallium bromide, gallium iodide, indium fluoride, indium chloride, indium bromide, indium iodide, yttrium chloride, yttrium bromide, yttrium iodide, titanium tetrakis (chloro/bromo/iodo), zirconium tetrakis (chloro/bromo/iodo), tetrakis (chloro/bromo/iodo) hafnium, tris (fluoro/chloro/bromo/iodo) iron, tris (fluoro/chloro/bromo/iodo) ruthenium, tris (fluoro/chloro/bromo/iodo) zinc, (fluoro/chloro/bromo/iodo) cadmium, (fluoro/chloro/bromo/iodo) mercury, (fluoro/chloro/bromo/iodo) tin, (fluoro/chloro/bromo/iodo) antimony, lanthanide (57-71) halides, trifluoromethanesulfonic acid (copper/tin/scandium/yttrium/zinc lanthanoids, etc.), trifluoroacetic acid (copper/tin/scandium/yttrium/zinc lanthanoids, etc.). Bronsted acids include hydrogen (fluoro/chloro/bromo/iodo) acid, trifluoroacetic acid, acetic acid, oxalic acid, phosphoric acid, sulfonic acid, methanesulfonic acid, benzenesulfonic acid, and the like. The lewis acid compound and the bronsted acid may be used singly, in combination of two or more kinds.

In an embodiment of the present invention, the second step specifically includes: and (3) mixing and washing the mixture obtained in the step one with a sodium hydroxide aqueous solution with the mass fraction of 1%, removing a water phase, transferring an oil phase into a solvent recoverer, and performing reduced pressure distillation to recover anisole.

And excessive anisole is recovered by distillation, so that the conversion rate of raw materials is improved, and the waste of materials is avoided.

In an embodiment of the present invention, the third step is specifically: adding an alcohol solvent and an ester exchange catalyst into a reaction container, dropwise adding preheated 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene into the reaction container, wherein the dropwise adding temperature is less than or equal to 40 ℃, reacting at 10-80 ℃ after completing dropwise adding until the residual quantity of 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is less than 1%, distilling at normal pressure to recover the alcohol solvent to obtain a crude anisyl propionaldehyde product, and then carrying out reduced pressure fast distillation and rectification on the crude anisyl propionaldehyde product to obtain the finished anisyl propionaldehyde product.

The side reaction can be reduced by dripping 1-acetoxyl group-2-methyl-3- (4-methoxyphenyl) propylene, thereby improving the conversion rate. The 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is preheated, so that the reaction activity of the 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene can be improved.

In an embodiment of the present invention, the alcohol solvent in the step three is at least one of methanol, ethanol, n-butanol, and n-propanol; the ester exchange catalyst in the third step is at least one of potassium carbonate, sodium methoxide, dilute sulfuric acid, sodium carbonate, sodium acetate and hydrochloric acid.

In an embodiment of the present invention, the preheating temperature of the 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene is 78-82 ℃.

The 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is preheated, so that the reaction activity of the 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene can be improved.

In a second aspect of the present invention, there is provided a method for preparing anisyl propionaldehyde from anisole, comprising the steps of:

s1, mixing anisole, 2-methylacrolein and acetic anhydride according to a molar ratio of (5-8): 1: (1.0-1.4) adding the mixture into a reaction container, cooling to-10-40 ℃, adding an alkylation reaction catalyst, and reacting at-10-80 ℃ until the residual amount of 2-methylallyl diacetate is less than 1%, so as to obtain a mixture for later use;

s2, mixing and washing the mixture obtained in the step S1 with an alkaline aqueous solution, transferring an oil phase into a solvent recoverer, and carrying out reduced pressure distillation to obtain 1-acetoxyl group-2-methyl-3- (4-methoxyphenyl) propylene for later use;

s3, adding 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene into a reaction container with an alcohol solvent and an ester exchange catalyst, reacting at 10-80 ℃ until the residual amount of 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is less than 1%, and distilling at normal pressure to obtain anisyl propionaldehyde.

The preparation process of the 2-methylacrolein and the acetic anhydride and the preparation process of the anisole and the 2-methylallyl diacetate can be synchronously carried out, so that the acetic anhydride and the anisole can be added into a reaction vessel together, and the generated 2-methylallyl diacetate reacts with the anisole to generate the intermediate 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propylene. Alternatively, 2-methacrolein may be added dropwise, or 2-methacrolein may be added at once, except that the yield of 2-methacrolein is lowered by a part by adding 2-methacrolein at once.

The reaction route of anisole, acetic anhydride and 2-methylacrolein is marked as B synthesis route of anisyl propionaldehyde:

b synthesis route of anisyl propionaldehyde: adding anisole, 2-methylacrolein and acetic anhydride into a reaction vessel, cooling to-10-40 ℃, starting adding an alkylation reaction catalyst, and controlling the temperature to be less than 40 ℃ when adding the alkylation reaction catalyst. After the alkylation reaction catalyst is added, the reaction temperature is controlled between-10 ℃ and 80 ℃ for reaction until the residual quantity of the raw material 2-methylacrolein is less than 1 percent. After the reaction, an appropriate amount of aqueous sodium hydroxide solution was added for washing, and the aqueous phase was separated. Transferring the oil phase into a solvent recoverer, and performing reduced pressure distillation to recover the unreacted excessive anisole. And adding the intermediate 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene after the solvent is recovered into a reaction vessel, and then adding a proper amount of alcohol solvent and an ester exchange catalyst. Controlling the reaction temperature to be 10-80 ℃ for reaction until the residual quantity of the intermediate is less than 1%. After the reaction, the solvent was recovered by atmospheric distillation. And then adding water to wash the crude anisyl propionaldehyde, then carrying out vacuum fast distillation, and finally rectifying the fast distilled crude product to obtain the finished anisyl propionaldehyde.

The two methods of the A synthetic route and the B synthetic route firstly obtain an intermediate 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene, and then the intermediate is hydrolyzed or transesterified in an alcohol solution to obtain anisyl propionaldehyde.

In an embodiment of the present invention, in the step S1, the molar ratio of anisole, 2-methacrolein and acetic anhydride is 6: 1: 1.2; the adding temperature of the alkylation reaction catalyst in the step S1 is 0-20 ℃; the reaction temperature in the step S1 is 20-40 ℃.

In one embodiment of the present invention, the alkylation catalyst is a lewis acid and/or a bronsted acid. The alkylation reaction catalyst includes boron trifluoride, boron trichloride, boron tribromide, boron triiodide, boron trifluoride-acetic acid compound, boron trifluoride-diacetic acid compound, boron trifluoride-diethyl ether compound, boron trifluoride-tetrahydrofuran compound, boron trifluoride-acetonitrile compound, boron trifluoride-dihydrate compound, boron trifluoride-n-butyl ether compound, boron trifluoride-methyl alcohol compound, boron trifluoride-phenol compound, boron trifluoride-phosphoric acid compound and the like, metal chlorides such as aluminum trifluoride, aluminum chloride, lithium bromide, aluminum iodide, scandium chloride, scandium bromide, scandium iodide, gallium fluoride, gallium chloride, gallium bromide, gallium iodide, indium fluoride, indium chloride, indium bromide, indium iodide, yttrium chloride, yttrium bromide, yttrium iodide, titanium tetrakis (chloro/bromo/iodo), zirconium tetrakis (chloro/bromo/iodo), tetrakis (chloro/bromo/iodo) hafnium, tris (fluoro/chloro/bromo/iodo) iron, tris (fluoro/chloro/bromo/iodo) ruthenium, tris (fluoro/chloro/bromo/iodo) zinc, (fluoro/chloro/bromo/iodo) cadmium, (fluoro/chloro/bromo/iodo) mercury, (fluoro/chloro/bromo/iodo) tin, (fluoro/chloro/bromo/iodo) antimony, lanthanide (57-71) halides, trifluoromethanesulfonic acid (copper/tin/scandium/yttrium/zinc lanthanoids, etc.), trifluoroacetic acid (copper/tin/scandium/yttrium/zinc lanthanoids, etc.). Bronsted acids include hydrogen (fluoro/chloro/bromo/iodo) acid, trifluoroacetic acid, acetic acid, oxalic acid, phosphoric acid, sulfonic acid, methanesulfonic acid, benzenesulfonic acid, and the like. The lewis acid compound and the bronsted acid may be used singly, in combination of two or more kinds.

In an embodiment of the present invention, the step S2 specifically includes: mixing and washing the mixture obtained in the step S1 with a sodium hydroxide aqueous solution with the mass fraction of 1%, removing a water phase, transferring an oil phase into a solvent recoverer, and performing reduced pressure distillation to recover anisole;

the step of S3 is specifically: adding an alcohol solvent and an ester exchange catalyst into a reaction container, dropwise adding 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene into the reaction container at the dropwise adding temperature of less than or equal to 40 ℃, reacting at 10-80 ℃ after dropwise adding until the residual amount of 1-acetoxyl-2-methyl-3- (4-methoxyphenyl) propylene is less than 1%, distilling at normal pressure to recover the alcohol solvent to obtain a crude anisyl propionaldehyde product, and then carrying out reduced pressure fast distillation and rectification on the crude anisyl propionaldehyde product to obtain the finished anisyl propionaldehyde product.

As mentioned above, the method for preparing anisyl propionaldehyde from anisole has the following beneficial effects: the anisole is used for synthesizing anisyl propionaldehyde, and as a brand new synthesis process, the traditional synthesis method using anisyl aldehyde or anisyl alcohol as a raw material is changed. The raw material anisole is cheap and easy to obtain, the production flow is short, the three wastes are less, and the method is economical and environment-friendly. The anisylpropionaldehyde synthesized is of sufficiently high purity to be useful in perfumery.

Drawings

FIG. 1 shows a process scheme of the A synthesis route of anisylpropionaldehyde in example 1 of the present invention.

FIG. 2 shows a process scheme of the B synthesis route of anisyl propionaldehyde in example 2 of the present invention.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Example 1

Preparation of anisyl propionaldehyde:

A. 1736.5g of acetic anhydride and 2.9g of boron trifluoride diethyl etherate (cat) are added into a 20L detachable separation bottle with a stirrer, a thermometer and a reflux condenser, 1071g of 2-methylacrolein is dripped into the bottle under the protection of inert gas, and the mixed system is stirred for 2 hours after the dripping is finished, so that the 2-methylallyl diacetate is prepared. Adding 8200g of anisole into the mixed solution, gradually dropwise adding 61.7g of boron trifluoride diethyl etherate solution, controlling the temperature of a reaction system between 20 and 40 ℃ after the dropwise adding is finished, continuing to react for 4 hours, mixing and washing the mixed solution by using a sodium hydroxide aqueous solution with the mass fraction of 1% after the reaction is finished, removing a water phase, collecting an organic phase, and recovering unreacted excessive anisole through reduced pressure distillation; 3373g of a reaction solution having a 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene content of 94.40% was obtained.

B. 3235g of methanol and 24.4g of potassium carbonate were mixed in a 10L separable flask equipped with a stirrer, a thermometer and a condenser, 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene was heated to 78 to 82 ℃, and then preheated 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene was added dropwise to the flask while stirring at 30 ℃. After the dropwise addition is completed, the mixture is stirred at 30-50 ℃ for about 5 hours to perform an ester exchange reaction. The conversion was complete at 98.0%. The unreacted methanol and by-product methyl acetate were then recovered by atmospheric distillation. Washing with water to obtain 2247g of crude anisyl propionaldehyde product with the purity of 94.1%. The crude anisyl propionaldehyde is put into a flask for vacuum rectification to obtain the finished anisyl propionaldehyde product, 2110g, with the purity of 99.2%.

Example 1 Synthesis of 2-methylallyl diacetate by reaction of acetic anhydride with pre-reacted 2-methylallyl diacetate in which anisole was reacted to form 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene and 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene was transesterified to anisylpropionaldehyde. The synthetic scheme of example 1 corresponds to the A synthetic route.

Example 2

Preparation of anisyl propionaldehyde:

A. 22.1g (300mmol) of 2-methacrolein, 36.8g (360mmol) of acetic anhydride and 151.5g (1410mmol) of anisole were put in a 300 ml three-necked flask equipped with a stirrer and a thermometer. 0.97g (6.0mmol) of anhydrous ferric chloride (cat) was slowly added while maintaining the reaction temperature between 5-45 ℃ and stirred for 5 hours. After the reaction was completed, 200ml of a 1% by mass aqueous solution of sodium hydroxide was added to the reaction product solution, and the stirring was continued for 10 minutes. Subsequently, the aqueous phase was separated, 200mL of a 1% by mass aqueous sodium hydroxide solution was further added to the organic phase, the mixture was stirred for 10 minutes, the aqueous phase was separated again, and the resulting organic phase was distilled to recover unreacted anisole. The remaining reaction solution was analyzed by HPLC (High Performance Liquid Chromatography), and the yield of 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propylene was 51.6g, which was 78%.

B. 50g of methanol and 1g of potassium carbonate were mixed in a 500mL separable flask equipped with a stirrer, a thermometer and a condenser, and after 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene was heated to 78 to 82 ℃, preheated 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene was added dropwise to the system at a temperature of < 30 ℃. After the dropwise addition is completed, the mixture is stirred at 30-60 ℃ for about 3 hours to perform an ester exchange reaction. The conversion was complete at 98.0%. The unreacted methanol and by-product methyl acetate are then recovered by distillation. The remaining concentrate was washed with water to give 30g (168mmol) of crude anisyl propionaldehyde having a purity of 93.6%.

Example 2-Methylacrolein, acetic anhydride and anisole were added together to a reaction vessel, the production of 2-Methylacrolein and acetic anhydride was synchronized with the production of anisole and 2-methylallyl diacetate, 2-Methylacrolein and acetic anhydride gradually produced 2-methylallyl diacetate, and the produced 2-methylallyl diacetate reacted with anisole to produce 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene, an intermediate of 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene, and anisyl propionaldehyde by transesterification of 1-acetoxy-2-methyl-3- (4-methoxyphenyl) propene. The synthetic approach of example 2 corresponds to the B synthetic route.

In conclusion, the invention synthesizes anisyl propionaldehyde from anisole, and as a brand new synthesis process, changes the traditional synthesis method which takes anisyl aldehyde or anisyl alcohol as raw materials. The raw material anisole is cheap and easy to obtain, the production flow is short, the three wastes are less, and the method is economical and environment-friendly. The anisylpropionaldehyde synthesized is of sufficiently high purity to be useful in perfumery. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.